Buggy code:
public abstract class SolrTestCaseJ4 extends LuceneTestCase { @ BeforeClass public static void beforeClassSolrTestCase ( ) throws Exception { } @ AfterClass public static void afterClassSolrTestCase ( ) throws Exception { } @ Override public void setUp ( ) throws Exception { } @ Override public void tearDown ( ) throws Exception { } public static void initCore ( String config , String schema ) throws Exception { } public static void initCore ( String config , String schema , String solrHome ) throws Exception { } static long numOpens ; static long numCloses ; public static void startTrackingSearchers ( ) { } static long zkClientNumOpens ; static long zkClientNumCloses ; public static void startTrackingZkClients ( ) { } public static void endTrackingSearchers ( ) { } public static void endTrackingZkClients ( ) { long endNumOpens = SolrZkClient . numOpens . get ( ) ; long endNumCloses = SolrZkClient . numCloses . get ( ) ; SolrZkClient . numOpens . getAndSet ( 0 ) ; SolrZkClient . numCloses . getAndSet ( 0 ) ; <START_BUG> if ( ( endNumOpens - ( SolrTestCaseJ4 . numOpens ) ) != ( endNumCloses - ( SolrTestCaseJ4 . numCloses ) ) ) { <END_BUG> String msg = ( ( "ERROR:<seq2seq4repair_space>SolrZkClient<seq2seq4repair_space>opens=" + ( endNumOpens - ( SolrTestCaseJ4 . zkClientNumOpens ) ) ) + "<seq2seq4repair_space>closes=" ) + ( endNumCloses - ( SolrTestCaseJ4 . zkClientNumCloses ) ) ; SolrTestCaseJ4 . log . error ( msg ) ; testsFailed = true ; fail ( msg ) ; } } public static void ignoreException ( String pattern ) { } public static void resetExceptionIgnores ( ) { } protected static String getClassName ( ) { } protected static String getSimpleClassName ( ) { } protected static String configString ; protected static String schemaString ; protected static SolrConfig solrConfig ; protected static TestHarness h ; protected static LocalRequestFactory lrf ; public static String getSchemaFile ( ) { } public static String getSolrConfigFile ( ) { } protected static File dataDir ; public static Logger log = LoggerFactory . getLogger ( SolrTestCaseJ4 . class ) ; private static String factoryProp ; public static void createTempDir ( ) { } public static void initCore ( ) throws Exception { } public static void createCore ( ) throws Exception { } public void postSetUp ( ) { } public void preTearDown ( ) { } public static void deleteCore ( ) throws Exception { } public static void assertU ( String update ) { } public static void assertU ( String message , String update ) { } public static void assertFailedU ( String update ) { } public static void assertFailedU ( String message , String update ) { } private static void checkUpdateU ( String message , String update , boolean shouldSucceed ) { } public static void assertQ ( SolrQueryRequest req , String ... tests ) { } public static void assertQ ( String message , SolrQueryRequest req , String ... tests ) { } public static String JQ ( SolrQueryRequest req ) throws Exception { } public static void assertJQ ( SolrQueryRequest req , String ... tests ) throws Exception { } public static void assertJQ ( SolrQueryRequest req , double delta , String ... tests ) throws Exception { } public static void assertQEx ( String message , SolrQueryRequest req , int code ) { } public static void assertQEx ( String message , SolrQueryRequest req , SolrException . ErrorCode code ) { } public static String optimize ( String ... args ) { } public static String commit ( String ... args ) { } public static String adoc ( String ... fieldsAndValues ) { } public static String adoc ( SolrInputDocument sdoc ) { } public static String add ( SolrTestCaseJ4 . XmlDoc doc , String ... args ) { } public static String delI ( String id ) { } public static String delQ ( String q ) { } public static SolrTestCaseJ4 . XmlDoc doc ( String ... fieldsAndValues ) { } public static ModifiableSolrParams params ( String ... params ) { } public static SolrQueryRequest req ( String ... q ) { } public static SolrQueryRequest req ( String [ ] params , String ... moreParams ) { } public static SolrQueryRequest req ( SolrParams params , String ... moreParams ) { } public static class XmlDoc { public String xml ; @ Override public String toString ( ) { } } public static boolean recurseDelete ( File f ) { } public void clearIndex ( ) { } public static String updateJ ( String json , SolrParams args ) throws Exception { } public static SolrInputDocument sdoc ( Object ... fieldsAndValues ) { } public static String json ( SolrInputDocument doc ) { } public static String jsonAdd ( SolrInputDocument ... docs ) { } public static String jsonDelId ( Object ... ids ) { } public static String jsonDelQ ( String ... queries ) { } public static Long addAndGetVersion ( SolrInputDocument sdoc , SolrParams params ) throws Exception { } public static Long deleteAndGetVersion ( String id , SolrParams params ) throws Exception { } public static Long deleteByQueryAndGetVersion ( String q , SolrParams params ) throws Exception { } public abstract static class Vals { public abstract Comparable get ( ) { } public String toJSON ( Comparable val ) { } protected int between ( int min , int max ) { } } public abstract static class IVals extends SolrTestCaseJ4 . Vals { public abstract int getInt ( ) { } } public static class IRange extends SolrTestCaseJ4 . IVals { final int min ; final int max ; public IRange ( int min , int max ) { } @ Override public int getInt ( ) { } @ Override public Comparable get ( ) { } } public static class FVal extends SolrTestCaseJ4 . Vals { final float min ; final float max ; public FVal ( float min , float max ) { }

Fix:
if ( ( endNumOpens - ( SolrTestCaseJ4 . zkClientNumOpens ) ) != ( endNumCloses - ( SolrTestCaseJ4 . zkClientNumCloses ) ) ) {